Closed Linux: memory read errors in assert packer and unpacker

A user reports being unable to use the mod I packed with asset_packer, so I decided to check out the packer and unpacker utilities with Valgrind on Linux. It reported problems both packing (first code quote) and unpacking (second code quote).

Code:

<jemalloc>: Error setting TSD for  
==25768== Invalid read of size 8 
==25768==  at 0x66AD51: ??? (in /home/matt/.config/Steam/steamapps/common/Starbound - Unstable/lin
ux/asset_packer) 
==25768==  by 0x5883C6: std::_Function_base::_Base_manager<std::_Bind<Star::Json (*(std::_Placehol
der<1>, std::_Placeholder<2>))(Star::Json const&, Star::Json const&)> >::_M_manager(std::_Any_data&,
std::_Any_data const&, std::_Manager_operation) (in /home/matt/.config/Steam/steamapps/common/Starb
ound - Unstable/linux/asset_packer) 
==25768==  by 0x5886EA: std::pair<Star::String const, std::function<Star::Json (Star::Json, Star::
Json)> >::~pair() (in /home/matt/.config/Steam/steamapps/common/Starbound - Unstable/linux/asset_pac
ker) 
==25768==  by 0x4E7F0B: ??? (in /home/matt/.config/Steam/steamapps/common/Starbound - Unstable/lin
ux/asset_packer) 
==25768==  by 0x7B903C: __libc_csu_init (in /home/matt/.config/Steam/steamapps/common/Starbound - 
Unstable/linux/asset_packer) 
==25768==  by 0x578A6BF: (below main) (in /usr/lib64/libc-2.23.so) 
==25768==  Address 0x0 is not stack'd, malloc'd or (recently) free'd 
==25768==  
==25768==  
==25768== Process terminating with default action of signal 11 (SIGSEGV) 
==25768==  Access not within mapped region at address 0x0 
==25768==  at 0x66AD51: ??? (in /home/matt/.config/Steam/steamapps/common/Starbound - Unstable/lin
ux/asset_packer) 
==25768==  by 0x5883C6: std::_Function_base::_Base_manager<std::_Bind<Star::Json (*(std::_Placehol
der<1>, std::_Placeholder<2>))(Star::Json const&, Star::Json const&)> >::_M_manager(std::_Any_data&,
std::_Any_data const&, std::_Manager_operation) (in /home/matt/.config/Steam/steamapps/common/Starb
ound - Unstable/linux/asset_packer) 
==25768==  by 0x5886EA: std::pair<Star::String const, std::function<Star::Json (Star::Json, Star::
Json)> >::~pair() (in /home/matt/.config/Steam/steamapps/common/Starbound - Unstable/linux/asset_pac
ker) 
==25768==  by 0x4E7F0B: ??? (in /home/matt/.config/Steam/steamapps/common/Starbound - Unstable/lin
ux/asset_packer) 
==25768==  by 0x7B903C: __libc_csu_init (in /home/matt/.config/Steam/steamapps/common/Starbound - 
Unstable/linux/asset_packer) 
==25768==  by 0x578A6BF: (below main) (in /usr/lib64/libc-2.23.so)

Code:

<jemalloc>: Error setting TSD for  
==25860== Invalid read of size 8 
==25860==  at 0x669561: ??? (in /home/matt/.config/Steam/steamapps/common/Starbound - Unstable/lin
ux/asset_unpacker) 
==25860==  by 0x585DC6: std::_Function_base::_Base_manager<std::_Bind<Star::Json (*(std::_Placehol
der<1>, std::_Placeholder<2>))(Star::Json const&, Star::Json const&)> >::_M_manager(std::_Any_data&,
std::_Any_data const&, std::_Manager_operation) (in /home/matt/.config/Steam/steamapps/common/Starb
ound - Unstable/linux/asset_unpacker) 
==25860==  by 0x5860FA: std::pair<Star::String const, std::function<Star::Json (Star::Json, Star::
Json)> >::~pair() (in /home/matt/.config/Steam/steamapps/common/Starbound - Unstable/linux/asset_unp
acker) 
==25860==  by 0x4E706B: ??? (in /home/matt/.config/Steam/steamapps/common/Starbound - Unstable/lin
ux/asset_unpacker) 
==25860==  by 0x7B784C: __libc_csu_init (in /home/matt/.config/Steam/steamapps/common/Starbound - 
Unstable/linux/asset_unpacker) 
==25860==  by 0x578A6BF: (below main) (in /usr/lib64/libc-2.23.so) 
==25860==  Address 0x0 is not stack'd, malloc'd or (recently) free'd 
==25860==  
==25860==  
==25860== Process terminating with default action of signal 11 (SIGSEGV) 
==25860==  Access not within mapped region at address 0x0 
==25860==  at 0x669561: ??? (in /home/matt/.config/Steam/steamapps/common/Starbound - Unstable/lin
ux/asset_unpacker) 
==25860==  by 0x585DC6: std::_Function_base::_Base_manager<std::_Bind<Star::Json (*(std::_Placehol
der<1>, std::_Placeholder<2>))(Star::Json const&, Star::Json const&)> >::_M_manager(std::_Any_data&,
std::_Any_data const&, std::_Manager_operation) (in /home/matt/.config/Steam/steamapps/common/Starb
ound - Unstable/linux/asset_unpacker) 
==25860==  by 0x5860FA: std::pair<Star::String const, std::function<Star::Json (Star::Json, Star::
Json)> >::~pair() (in /home/matt/.config/Steam/steamapps/common/Starbound - Unstable/linux/asset_unp
acker) 
==25860==  by 0x4E706B: ??? (in /home/matt/.config/Steam/steamapps/common/Starbound - Unstable/lin
ux/asset_unpacker) 
==25860==  by 0x7B784C: __libc_csu_init (in /home/matt/.config/Steam/steamapps/common/Starbound - 
Unstable/linux/asset_unpacker) 
==25860==  by 0x578A6BF: (below main) (in /usr/lib64/libc-2.23.so)